Automatic firearm



' .J. E. BROWNING v 3 8,

AUTOMATIC FIREARM Filed Jan. 28, 1951 2 Sheets-Sheet 1 Aug. 18, 1931.

J. E. BRO NING AUTOMATIC FIREARM Filed Jan. 28, ,1931

,1 [2 5 E J fi kt arn yi Patented Aug. 38, 193i 2 iii rent JOEATEAN EDMUND BROWNDTG, OF OGDEN, UTAH, ASSIGNOR T 3'. E. BROWNING COMPANY, OF OGDEN, UTAH, A CORPORATION OF UTAH au'romnrrc Brennan:

Application filed January 28, 1931. Serial No. 511,741.

' ual operation of the trigger to efiect the firing of each shot. In regard to this latter feature, however, 1 do not necessarily limit myself and as concerns some of its phases the invention is applicable to firearms adapted for full automatic or volley firing.

The invention relates particularly to a firearm, such as disclosed in my copending applications for automatic firearms, Serial No. 262,818 filed MarchlS, 1928, and Serial No. 391,67 5 filed September 10, 1929, wherein the barrel and barrel extension and also the breech slide or bolt move rearward uponrecoil to a limited extent and wherein the breech bolt is then permitted to move rearward separate from and to a greater extent than the barrel and barrel extension, being returned to its forward locked position automatically. The separate rearward movement of the breech bolt eiiects the extraction and ejection of the cartridge shell, efiects the cooking of the firing mechanism and effects the transfer of a cartridge from the magazine to the firing chamber.

One of the objects of the present invention is to provide an improved means for insuring a proper relative timing of the recoil and counter-recoil movements of the barrel ex tension and the breech bolt.

A further object of the invention is to provide an improved mechanism for holding the breech bolt in its rear-most position after the last cartridge in the magazine or clip has been fired.

Further objects of the invention will be apparent from the following specification and claims.

In the accompanying drawings 1 have shown the embodiment of the invention which I now deem preferable but it will be understood that the drawings are intended for illustrative purposes only and are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for, that purposes.

Of the drawings:

Fig. l is a right side View of a firearm embodying the invention.

Fig. 2 is an enlarged fragmentary longitudinal sectional view taken from the right;

Fig. 3 is a transverse vertical sectional View taken along the line 3+3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2 but showing the parts in difierent relative positions.

Figs. 5, 6, 7 and 8 are enlarged fragmentary views which are partly diagrammatic and which show the action whereby the barrel extension and breech bolt are maintained in proper timed relation.

Fig. 9 is an enlarged fragmentary longitudinal sectional view showing cartridge supply mechanism and associated parts.

Fig. 10 is a rear view of the cartridge clip,

this view being on the same scale as Fig. 9.

In the drawings Fig. 1 is a right side view of the gun as a whole, the receiver being shown at 1, the barrel at 2, the breech bolt at 3, the breech cover at 4, the stock at 5, the barrel jacket at 6, and the barrel cover at 7.

As shown in Figs. 2 and 4, the receiver 1 is connected at its front end with the rear end of the barrel jacketfi, a threaded connection being shown. The receiver 1 is provided with parallel longitudinal side walls 8, 8 which are adapted to receive between them the barrel extension 9 and to serve as guides controlling the longitudinal movement thereof. At the rear the receiver 1 is connected with the reaction spring tube 10 which extends rearward and downward. Connected with the receiver at the bottom thereof is a member 11 having a substantially rectangular cartridge opening 12 therein, this opening being in register with a similar opening in the top of the receiver. The member 11 has the trigger guard 11 formed thereon, and it also supports certain operative parts of the gun as will presently appear.

The barrel 2 and the barrel extension 9 are suitably connected together as by threading and the barrel is provided at the rear with the usual cartridge chamber 13. The barrel extension is formed to receive the breech bolt 3, and it is further formed with suitable guide portions adapted to fit between and be guidedby the side walls 8, 8

a is completely assembled the barrel and barrel extension have only a limited movement with respect to the receiver. The barrel extension is providedwith a relatively large bottom opening adapted to register with the cartridge opening 12 and to permit the passage of cartridge clips therethrough as will be presently explained. At the rear of the said opening the barrel extension is formed with a forward facing shoulder 14.

Fig. 2 shows the breech bolt 3 in its normal relationship with the other parts of the gun. The main'body of the breech bolt ispreferably of unitary construction, having all of its parts rigidly maintained in fixed relation to each other. At the sides of the breech'bolt near the front are guide flanges 15 which normallyenter and loosely fit guide grooves 16 inthe side walls of the barrel extension. The breech bolt 3 is held in its forward position by means of a strut 17 pivotally connected with the rear portion of the said bolt. The rear end of thestrut 17 engagesa plunger 18 which is slidable inthe reaction spring tube 10. The reaction spring 19 in the said tube serves to push the plunger18 forward andthus through the strut 17 serves to push the breech bolt3 forward and yieldingly hold it in its forward position.

The breech bolt 3 has a downward projecting lug 20, the rear face of which normally engages the shoulder 14: on the barrel ex-v tension. When the lug and the shoulder are thus engaged the breech bolt and barrel extension are positivel locked together in the proper position for bring. Upon recoil unlocking is effected by causing the rear part of the breech bolt to move transversely or diagonally with respect to the direction of movement of the barrel extension. The front end of the bolt moves directly rearward, being guided by the grooves 16, and the bolt is thus given an angular or tilting movement about a transverse axis near the front end thereof.

Figs. 2 and 4: show the breech cover 4 in its operative relationship with the other parts, but it will be understood that the said cover is readily removable. The breech cover 4 has at the front a downwardprojection 21 which is adapted to engage an upward pro-.

jection 22 on the breech bolt as shown in Fig.

2, the-said projections being provided rethe lug 20 to become disengaged from the shoulder 14.

As alreadystated the breech bolt and barrel: extension are directly locked together when in the firing position. When firing oclinearly in unison with them. Then the rear part of the breech bolt is moved transversely or diagonally upward and rearward until the lug 20 is disengaged from the barrel extension. After disengagement the breech bolt continues to move rearward and the motion of the barrel extension and barrel is stopped.

Mountedin the receiver is a member 25 which I will refer to as an accelerator. The accelerator is pivotally mounted on a transverse pin 26 which extends into bearin apertures in the receiver. The main body portion of the accelerator is curved upward and rearward, having a convex forward facing surface which is adapted to cooperatively engage a flat rearward facing surface near the rear end of the barrel extension. By reason of the engagement of'the accelerator with the flat surface of the barrel extension the said accelerator is moved in the counterclockwise direction until the upper end thereof engages the breech bolt at 27. The turning is such that, when the accelerator engages the breech bolt as stated, the breech bolt has moved rearward 'sufiiciently to permit the flat horizontal surfaces of the projections 21 and 22 to disengage each other,

- which enables it to move 1n opposition to the spring 19 approximately to the position shown in Fig. 4, being guided in part by the inner surface of the cover. During its separate'rearward movement the breech bolt is guided in part by the before-mentioned flanges 15 which enter grooves 28 formed in the barrel extension. It will be seen that the accelerator. serves to transfer the energy of the moving barrel and barrel extension to the said breech bolt, the result being that the movement of the barrel and barrel extension is gradually retarded and finally stopped while the absorbed energy is imparted to the breech 'bolt'to throw it tion of recoil. k

,As clearly indicated ,in Fig. 4 the lower surface of the lug 0f the breech bolt remains in engagement. with the accelerator during the separate rearward and return movements of the breech bolt. Thus the ac celerator is held in its rearmost position as indicated. It will be observed that the lower surface of the lug 20 is so inclined with respect to the main body of the bolt that upon angular movement of the bolt it assumes a position parallel with the direction of the separate rearward movement. Thus, the -15" accelerator is held immovable during such movement.v I I There is provided a stop 29 .,on the barrel extensionwhich is engaged by the accelerator 25 when the extreme position is reached, the

said accelerator being provided with a surface at 30 to engage the said stop. The en,- gagementof the stop with the accelerator prevents further rotative movement of the latter and at the same time a shoulder 31,

on the accelerator engages the bottom of the barrel extension.

As soon as the breech bolt reaches its rearmost position as shown in Fig.4 it is immediately returned in the forward direction by reason of the action of the spring 19 and associated parts. As the breechbolt moves forward the lug 20 releases'the accelerator and immediately thereafter the forward facing surface at 27 re-engages the accelerator and causes it tomove in the clockwise direction to the position shown in Fig. 2. As the accelerator moves in the clockwise direction the barrel and barrel extension move forward in unison with the breech bolt but at a slowerspeed. As-soon as the parts reach the proper position the cam surfaces 23 and 24 engage with eachother, the result being a that as the breech bolt continues to move forward it is returned to its locked relationship with the barrel extension. The final movement of the breech bolt in the forward direction carries the barrel and barrel ex- 7 tension with it in locked relationship, thus completely restoring the parts to the relationship shown in Fig. 2. In accordance with I provide-novel means for maintaining the proper timed relationship of the barrel extension and breech bolt during their recoil .ship with other and counter-recoil movements, particularly during the latter. For this purpose I provide what I will term a timing cam 32 which is directly connected with or formed as a part of the accelerator. I The action of the timing cam 32 and its cooperative relationparts are. shown clearly in Eigs5to8. I Duringcounter-recoil movement the accelerator is moved in the clockwise direction,

movement being eifectedby means-of the rearward to the posibolt, as shown in Fig. 5. The timing cam 32 he present invention forward facin surface at 27 on the breech is positioned to project upward into the space between the left hand side of thebreech the said cam is in engagement or substantially in engagement with the said lug 33. It

will be understood that at the same time the forward facing surface of the accelerator proper remains in engagement with the rearward facing surface of the barrel extension. It will thus be apparent that the combined accelerator and tlming cam is held in predetermined relationship with the barrel extension, movementof the barrel extension being possible only when the timing element is correspondingly moved.

The cam 32 retards forward movement of the barrel extension, and the inclination of the cam is such as to make impossible any movement of the cam and accelerator by reason of forward pressure exerted on the cam by the barrel extension. The acceleratorand cam are moved only by the forward moving breech bolt as already explained, and it is,

therefore, impossible for the barrel extension to move forward too rapidly so as to get out of proper timed relation with the breech bolt. Fig. 6 shows the accelerator and cam moved to an. intermediate positionby the breech bolt, but theengagement of the cam with the abutment 33 prevents any excess movement of the barrel extension in the forward direction. Fig. 7 shows the accel-. erator and cam moved to the position where locking is about to take place. The caI n has now moved nearly-to a position in whlch 1t no longer retards the barrel extension, and

the barrel extension and breech bolt'can move forward in unison to the position shown in Fig.8. I I The breech bolt 3 carries at the rightside thereof a handle 34 which may be used to manually operate the mechanism of the gun.

It be understood that upon manual movement the operation of the as already described. Mounted within th i'ng pin whichv is not shown infdetail as it parts is the same invention. This firing pin is a apted to. prosear 36 mounted in the breech bolt. The sear is provided'with adownward hook extension 37 adapted to be engaged by the I trigger lever as will presently be described.

mama 3 is a firdoes not in itself constitutean part of the v A spring is provided 4 new for normally pressing the sear u ward. v The coc 'ng lever is shown at 38, being pivotally mountedon the breech bolt for move ment about a transverse axis. When 1 the breech bolt moves 'r earward as already described the cocking lever is forced against a shoulder 39 on the receiver and it then travels along a surface 40 on the receiver as shown in Fig. 4. The cockin lever in moving from the position shown in Fig. 2 to the position shown in Fig. 4 moves the firing pin relatively rearward into position to be engaged by-the sear 36.

It will be understood that as the breech bolt moves rearward it. extracts and ejects the shell of the cartridge that has been fired, suitable exiracting and ejecting devices beings supplied for this purpose. These devices constitute no part 0 the present invention and i are not shown. They may be constructed as disclosed in my copending applications be.- fore referred to.

The trigger 41 is pivotally mounted at 42 on the member 11 and projects downward I through an aperture in the said member adjacent the guard 11". The trigger is provided at the top with a cam surface which engages the bottom face of a lever 43 pivoted at 44 to the member 11. Pivoted to the lever 43 is a hooked link 45 which is adapted to detachably engage the hooked portion '37 of the sear when the parts are in the firing 'po-. sitionsas shown in Fig. 2. The link 45 and the lever 43 are both pressed in the counterclockwise direction by a spring 46. When the trigger is pulled toward the rear the lever 43 is turned in the clockwise direction and the link and the sear 36 are pulled downward to relase the firing pin 35. i

I have shown a safety mechanism which is in many respects similar to that disclosed in my aforesaid copending application Se- 1 rial No. 391,675. There is provided a safety.

prevent movement. of the trigger.

lever 47 which is pivotally mounted at 48 on a stud carried by the receiver at the left side. At the forward end of the lever47 is an upward extenison 49 which is adapted to project into the path of movement of the rear end of the breech bolt. The safety lever is furtherprovided with a lug at 50 which is adapted to engage the trigger lever 43 and.

The lever 47 can be operated by means of the manually operable lever 51 which is pivoted at 52 to the detachable cover 4. The upper end of the lever 51 carries a finger piece 53 which is exposed at the left of the cover and the lower end detachably engaged with the lever 47 as shown. By manually operating the lever 51 the lever 47 can be moved in the counterclockwise direction from the position shown in Figs. 2 and 4 and when so moved it locks the breech bolt and the trigger, thus efi'ecv tively preventing firing.

As already stated, openings are provided in the receiver and in the barrel extension which register with the cartridge opening 12 and it will therefore be seen that there is in effect a cartridge opening which extends entirely through the fire-arm from top to bot- 7 tom thereof. This opening is adaptedfor receiving cartridge clips 54 which are passed through the fire-arm from top to bottom. Each clip 54 is open at the top, bottom and front, but is closed or substantially closed at v the rear.- As shown most clearly in Figs. 9 and 10 each cartridge cli 54 is formed of sheet metal and is prefera ly of such width as'to holdtwo rows of cartridges as shown. v-

The side walls of the clip 54 are bent inward slightly at the top and bottomasshown at 55,. to assist in holding the cartridges in place, and the said side walls arealso providedwithf inward bent ribs 56 to enter the grooves in the cartridges to also assist in holding them in place. The rear wall of the clip 54 is preferably bent to form a rearward projecting rib 57 and the rear portion of this rib is partly cut away to form atleast one opening 58. Preferably the clip is reversible so that it can be inserted in the firearm either side up and in this'case there are two similar openings 58 similarto each other and similarly located with respect to pivoted at 61 to the rear end of the follower,

and pivoted at 62 to the main frame or receiver of the firearm at the front of, the opening 12. Pivotedto the link between the ends thereof is a second link 63, one end of which presses against the follower 59. The other end of the link 63 is curved and engages a suitable fixed abutment 64. A spring 65 tends to move the link 60 in the clockwise direction, thus pressing the follower 59 upward. The curved end of the link 63 is so shaped that the said link serves to support the forward portion of the follower 59 and to cause it to move upward in substantial parallelism.

lVith the loaded clip 54 in place as shown in Fig. 4, the follower 59 and also the links 60 and 63 are in their lowermost positions. Mounted on the member 11 is a spring pressed pivoted detent 66 which enters the lower opening 58 in the clip, thus preventing the vretain the breech bolt in its rearmost position clip from being moved upward as the result of pressure exerted by the follower 59.

Forward movement of the breech bolt from the position shown in Fig. 4, removes the foremost cartridge from the clip and advances it into the chamber 13 of the barrel and effects firing thereof. Upon pulling the trigger firing then takes place and the recoil action of the breech bolt and other parts follows in the manner already described. Upon each return movement ofthe breech bolt-a,

cartridge is withdrawn from the clip and advanced into the firing chamber, this action continuing until the clip is entirely empty.

At the rear of the cartridge opening 12 there is provided a vertically movable stop 67 .which is normally held in its lowermost position by means of a spring 68. These parts are shown particularly clearly in Fig. 9. The stop 67 is so, constructed that when moved upward its upper end lies-in the path of movement of the breech bolt and thus serves to as clearly shown in Figs. 4 and 9. Carried by the stop 67 is an element 69 which normally projects forward into the path of upward movement of a lug on the follower 59.

These partsare so related that the follower engages the said element 69 after the last cartridge has been removed from the clip and moves the said-element 69 and the stop 67 upward. The result is that the stop 67 is positioned in the path of movement of the breech bolt and holds the breech bolt in its rearmost position as already stated. It will be understood that the breech bolt exerts suflicient pressure on the stop 67 to hold it in its u per position even though the follower 1s -.moved downward. The breech bolt can be released after the insertion of a' loaded clip by pulling backward on the handle 34 so as to p release the breech bolt on the stop 67.

Preferably the element 69 projects through the upper opening 58 in the clip, the opening being of suflicient length to permit the necessary movement of the said element. The said element 69 is pivoted and is normally held in its projecting position by a spring pressed plunger 71.

Fig. 9 shows the procedure of replacing an empty cartridge clip with a loaded one.

ing. The loaded clip engages the empty one and pushesit downward,the spring detent 66 being pushed back out of the way. The empty and loaded clips as they move downward push the'element ,69frearward and, it finally projects into the upper opening 58 in the loaded clip. As the loaded clip moves downward the follower 59 isalso moved downward to its lowermost position as shown in Fig. 4.

What I claim is:

1. A firearm of the class described comprising in combination, a receiver, a barrel and barrel extension movable upon recoil rearward relatively to the receiver, a rearward -movable breech bolt normally in locked engagement with the barrel extension, means operativeduring recoilfor unlocking the bolt from the extension and operative during counter-recoil for restoring the locked relationship, an accelerator pivoted to the receiver for movement about a fixed transverse axis and connected with the barrel extension for movement therewith, the said accelerator servingupon recoil to move the breech bolt :rearward separately from the barrel extension, and a "cam on the accelerator engaging the barrel extension to retard forward movement thereof during the counter-recoil'movement of the bolt, the inclination of the said cambeing such as to prevent turning thereof barrel extension.

2.- A firearm as set forth in claiml, wherein the breech bolt engages the accelerator to hold it in its rearmost position during the separate rearward and forward movements of the bolt, and wherein the cam on the accelerator engages the barrel extension when the accelerator is in its rearmost position.

by forward. pressure exerted thereon by the I 3. Afirearm as set forth in claim 1, where'- i of thebreech bolt transversely with respect to the barrel extension.

4. In a firearm of the class described, the combination of areceiver having a cartridge opening extending vertically therethrough for receiving at the top a cartridge clip which is'open at the top, bottom and front and closed at the rear, a breech bolt movable rearward upon recoil and automatically returned to its normal position, a follower on the firearm adapted to enter the cartridge clip at the bottom and move cartridges successively upward out of the clip into the path of return movement of the bolt, and a stop mechanism at the rear of the cartridge opening adapted to be engaged by the follow- 'er and moved upward into the path of return movement of the bolt after the last cartridge has been removed from the clip, the said stop mechanism including an element yieldable to permit a loaded clip to be inserted at the top and the empty. clip to be discharged at the bottom. I

5. A firearm as set forth in claim 4, wherein the sto mechanism comprises a substantially vertically movable plunger and an element horizontally pivoted on the plunger and normally projecting into the path of move- ,ment of the follower; g

l 6. In a firearm of the class described, the

combination of a receiver havin a cartridge opening extending vertically t erethrough, a cartridge clip adapted to enter the cartridge opening at the top, the said clip being open at the top, bottom and front and having a small opening in its rear wall, a breech bolt movable rearward upon recoil and automatically returned to its normal position, a follower on the firearm adapted to enter the cartridge clip at the bottom and move cartridges successively upward out of the clip into the path of return movement of the bolt, a stop at the rear of the cartridge opening adapted to be moved upward into the path of return movement of the bolt, and an element connected with the stop and normally projecting through the opening in the rear wall of the clip so as to be engaged and moved upward by the follower when the last cartridge has 2 been removed from the clip, the said element being yieldable to permit the empty clip to be discharged at the bottom and a loaded clip to be inserted at the top.

7 In a firearm of the class described, the combination of a receiver having a cartridge opening extending vertically therethrough,

a cartridge clip adapted to enter the cartridge opening at the top and. similarly formed at both ends so as to be reversible, the said clip being open at the ends and at the front and also having its rear wall cut away to a limited extent, a breach bolt movable rearward upon recoil and automatically returned to its normal position, a follower on the firearm adapted to enter the cartridge clip at the bottom and move cartridges successively upward out of the clip into the path of v return movement of the bolt, a stop at the rear of the cartridge opening adapted to be moved upward into the'path'of return move ment of the bolt, and an element connected with the stop and normally projecting" through the rear wall of the clip with the clip in either of its relatively reversed positions so as to be engaged and moved upward by the follower when the last cartridge has been removed from the clip, the said element being yieldable to permit the empty clip to be discharged at the bottom and a-loaded clip to be inserted at the top.

8. A firearm asset forth in claim 7, wherev in the cartridge clip has two' similar openings in its rear wall and isthus adapted to be reversed in position.

9f A'firearm as set forth in claim 7, where inthe cartridge clip has two similar openings in its rear wall and is thus adapted to be reversed in position, and wherein there is provided a detent adapted to enter the opening which is not entered by the yieldable element. on the stop.

In testimony whereof I have hereuntoset' my hand this 20th day of January, 1931.

I JONATHAN EDMUND BROWNING. 

